Men with higher levels of testosterone have weaker immune systems then both women and the 90-pound weaklings they stuffed into their high-school lockers, a new Stanford study found.

“There are marked differences between the sexes in their immune response to infections and vaccination, with females often having significantly higher responses,” reads the study, which was posted on Proceedings of the National Academy of Sciences.

Men with high testosterone levels showed the lowest antibody response to flu vaccinations.